Data Link Layer Design Challenges

Data Link Layer Design Issues

• The data link layer addresses issues of reliable data transmission between adjacent nodes.
• Key concerns include error detection and correction, flow control, and addressing.

Error Detection and Correction in the Data Link Layer

• Hamming code is a powerful error-correcting code that adds redundant bits to data for error detection and correction.
• CRC (Cyclic Redundancy Check) uses polynomial division to generate a checksum for error detection.
• Parity checks add a single bit to detect single-bit errors.
• Checksums involve summing data segments (often using modular arithmetic) for error detection.

Switch Operation in the Data Link Layer

• Switches operate at the data link layer, making forwarding decisions based on MAC addresses.
• They use techniques like learning and flooding to forward frames efficiently.
• Switches can create virtual LANs (VLANs) to segment and manage network traffic logically.

Elementary Data Link Protocols

• Several elementary protocols govern the basic exchange of data at this layer.
• Examples can include protocols that handle frame formatting, address resolution, and flow control at a simple level.
• These might be used in point-to-point or simple multi-access networks.